Equipment service vehicle having on-board diagnostic system

ABSTRACT

An equipment service vehicle comprises a network communication link, an engine system, a transmission system, and an operator interface. The engine system includes an engine and an electronic engine control system that is coupled to the engine and to the network communication link. The electronic engine control system controls the engine and transmits information pertaining to the health and operation of the engine on the network communication link. The transmission system includes a transmission and an electronic transmission control system. The electronic transmission control system controls the transmission and transmits information pertaining to the health and operation of the transmission on the network communication link. The operator interface is coupled to the network communication link. The operator interface includes a display that displays the health and operation information of the engine and the transmission to a human operator.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation of U.S. Ser. No. 09/500,506,filed Feb. 9, 2000, now U.S. Pat. No. 6,553,290, issued Feb. 22, 2003,hereby incorporated by reference.

FIELD OF THE INVENTION

[0002] This invention relates to diagnostic systems for equipmentservice vehicles. In particular, this invention relates to an on-boarddiagnostic system for equipment service vehicles.

DESCRIPTION OF RELATED ART

[0003] Modern vehicles have become increasingly complex and difficult tomaintain. In order to enable more efficient vehicle maintenance, it isdesirable to be able to accurately diagnose malfunctioning subsystems,such as engine systems, transmission systems, and so on, as well asspecific vehicle components. When a malfunction is not properlydiagnosed, the result is typically that parts which are fullyoperational are repaired or replaced, that parts which are repairableare replaced, and/or that parts which are not fully operational are notrepaired or replaced. Accurate diagnoses therefore allow more efficientvehicle maintenance by avoiding unnecessary repairs and replacements,and by enabling necessary repairs and replacements to be made.

[0004] It is known to provide electronic diagnostic systems to aid inthe accurate diagnoses of vehicle malfunctions. Government Report No.CR-82-588-003, entitled “STE/ICE-R Design Guide For Vehicle DiagnosticConnector Assemblies,” February 1988, describes a diagnostic system usedin connection with military vehicles. According to the approachdescribed in this document, a military vehicle is provided with numeroussensors that are located throughout the vehicle and each of whichobtains information pertaining to the health and operation of asubsystem of the vehicle. The sensors are used to measure typicalparameters of interest such as engine RPM, engine temperature, fuelpressure, and so on. The sensors are connected by way of vehicle wiringto a common connector assembly. Diagnostic equipment provided at amaintenance depot is then capable of connecting to the various sensorsby way of the connector assembly. At the maintenance depot, thediagnostic equipment can be utilized to perform tests on the vehicle toaid pinpointing the source of vehicle system malfunction.

[0005] In this arrangement, the sensors that are used by the diagnosticsystem are used exclusively by the diagnostic equipment at themaintenance depot, and not by other systems during normal operation ofthe vehicle. Additionally, in this arrangement, the connector assemblydefines a hardwired analog interface between the sensors and thediagnostic equipment, and the diagnostic equipment expects signalsappearing at given pins of the connector assembly to have predefinedsignal characteristics that are unique to the sensor utilized.

[0006] This approach suffers several disadvantages. First, this approachis expensive to implement because it requires numerous sensors above andbeyond those required for normal operation of the vehicle. Additionally,the required sensors typically have unique signal characteristics thatare specifically matched to the diagnostic equipment, and therefore thesensors are specialty items that are more expensive and not commonlyavailable.

[0007] Second, this approach results in a diagnostic system with anunduly limited capability to accurately diagnose system faults. Thecapabilities of the diagnostic system are limited by the fact that thediagnostic system only utilizes information that is available from thediagnostic system sensors and not from other sources of informationavailable on-board the vehicle. Therefore, the number of different typesof information that can be obtained is limited to the number ofdiagnostic system sensors utilized. Further, because the sensors thatare utilized tend to be specialty items as previously noted, they oftendo not incorporate the latest advances in sensor technology that provideperformance/durability improvements over earlier sensor technologies.This further limits the accuracy of the diagnostic system as compared tothat which could otherwise be achieved.

[0008] Finally, this approach is unduly cumbersome to utilize. Aspreviously noted, the diagnostic equipment is provided at a maintenancedepot and not on-board the vehicle. Therefore, in order to have avehicle malfunction diagnosed, the vehicle must be brought to themaintenance depot. This requirement is inconvenient and limits thepotential for field servicing of vehicles to minimize the amount of timethat the vehicle is out of service for maintenance reasons.

SUMMARY OF THE INVENTION

[0009] The present invention overcomes the problems of conventionaldiagnostic systems for equipment service vehicles. In particular, in oneparticularly preferred embodiment, the invention provides an equipmentservice vehicle comprising a network communication link, a plurality ofvehicle subsystems, a test control module, and an operator interface.The vehicle subsystems each comprise a mechanical system and anelectronic control system that controls the mechanical system. Forexample, one vehicle subsystem may comprise an engine and an enginecontrol system, and another vehicle subsystem may comprise atransmission and a transmission control system. Each respectiveelectronic control system is connected to the network communication linkand transmits information pertaining to the health and operation of theassociated mechanical system on the network communication link. The testcontrol module is coupled to the plurality of vehicle subsystems by wayof the network communication link. The test control module is programmedto acquire at least some of the information pertaining to the health andoperation of the mechanical system. The operator interface is coupled tothe test control module and comprises a display that displays the atleast some information pertaining to the health and operation of themechanical system.

[0010] According to another particularly preferred embodiment of theinvention, the invention provides a method of diagnosing a fault on anequipment service vehicle comprising providing the equipment servicevehicle with an on-board diagnostic system. The on board diagnosticsystem comprises a test control module and an operator interface thatare mounted on the vehicle. The method also comprises displaying a menuof test options to an operator using the operator interface andreceiving an operator input using the operator interface. The input isindicative of a menu selection made by the operator, and the menuselection indicates a test selected by the operator to be performed onthe vehicle. Further, the method comprises performing the selected teston the vehicle in response to the operator input, and displaying resultsof the test to the operator using the operator interface.

[0011] According to yet another particularly preferred embodiment of theinvention, the invention provides an equipment service vehiclecomprising a network communication link, an engine system, atransmission system, and an operator interface. The engine systemincludes an engine and an electronic engine control system that iscoupled to the engine and to the network communication link. Theelectronic engine control system controls the engine and transmitsinformation pertaining to the health and operation of the engine on thenetwork communication link. The transmission system includes atransmission and an electronic transmission control system. Theelectronic transmission control system controls the transmission andtransmits information pertaining to the health and operation of thetransmission on the network communication link. The operator interfaceis coupled to the network communication link and includes a display thatdisplays the health and operation information of the engine and thetransmission to a human operator.

[0012] Other objects, features, and advantages of the present inventionwill become apparent to those skilled in the art from the followingdetailed description and accompanying drawings. It should be understood,however, that the detailed description and specific examples, whileindicating preferred embodiments of the present invention, are given byway of illustration and not limitation. Many modifications and changeswithin the scope of the present invention may be made without departingfrom the spirit thereof, and the invention includes all suchmodifications.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a schematic view of a military vehicle having adiagnostic system according to one embodiment of the present invention;

[0014]FIG. 2 is a block diagram of the diagnostic system of FIG. 1showing selected aspects of the diagnostic system in greater detail;

[0015]FIG. 3 is a menu displayed by a display of the diagnostic systemof FIG. 1 showing various services offered by the diagnostic system;

[0016]FIG. 4 is a flow chart showing the operation of the diagnosticsystem of FIG. 1 to perform a diagnostic test procedure;

[0017]FIG. 5 is a schematic view of a firefighting vehicle having adiagnostic system in accordance with FIGS. 1-4;

[0018]FIG. 6 is a schematic view of a mixing vehicle having a diagnosticsystem in accordance with FIGS. 1-4;

[0019]FIG. 7 is a schematic view of a refuse handling vehicle having adiagnostic system in accordance with FIGS. 1-4; and

[0020]FIG. 8 is a schematic view of a snow removal vehicle having adiagnostic system in accordance with FIGS. 1-4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Referring now to FIG. 1, a preferred embodiment of an equipmentservice vehicle 10 having a diagnostic system 12 according to anembodiment of the invention is illustrated. By way of overview, thediagnostic system 12 comprises an intelligent display module 14, a testinterface module 21 connected to a plurality of sensors 22, and aplurality of additional vehicle control systems 24-30. The intelligentdisplay module 14, the test interface module 21, and the plurality ofadditional vehicle control systems 24-30 are interconnected with eachother by way of a network communication link 32.

[0022] More specifically, the vehicle 10 is a military vehicle and, inparticular, a medium tactical vehicle. However, it should be understoodthat the diagnostic system 12 of FIG. 1 could also be used with othertypes of military vehicles. For example, the diagnostic system 12 couldbe used in connection with heavy equipment transporter vehicles, whichare used to transport battle tanks, fighting and recovery vehicles,self-propelled howitzers, construction equipment and other types ofequipment. These types of vehicles are useable on primary, secondary,and unimproved roads and trails, and are able to transport in excess of100,000 pounds or even in the range of 200,000 pounds or more. Thediagnostic system 12 can also be used in connection with palletized loadtransport vehicles, in which a mobile truck and trailer form aself-contained system capable of loading and unloading a wide range ofcargo without the need for forklifts or other material handlingequipment. Such trucks are provided with a demountable cargo bed and ahydraulically powered arm with a hook that lifts the cargo bed on or offthe truck. These trucks may be also provided with a crane to drop offthe pallets individually if the entire load is not needed. Further, thediagnostic system 12 can also be used in connection with trucks designedfor carrying payloads for cross country military missions. Such trucksmay include, for example, cargo trucks, tractors, fuel servicing trucks,portable water trucks, and recovery vehicles (with crane and winch).Such trucks are capable of passing through water crossings three or fouror more feet deep. These trucks can also be used for missiletransports/launchers, resupply of fueled artillery ammunition andforward area rearm vehicles, refueling of tracked and wheeled vehiclesand helicopters, and recovery of disabled wheeled and tracked vehicles.The diagnostic system 12 can be used in connection with a wide range ofother military vehicles as well.

[0023] The intelligent display module 14 provides an operator interfaceto the diagnostic system 12 and also provides intelligence used toconduct diagnostic tests and other services. In particular, theintelligent display module 14 includes a test control module 15 (whichfurther includes a microprocessor 16 and a diagnostic program 17) and anoperator interface 18 (which further includes a display 19 and a keypad20) (see FIG. 2).

[0024] In the preferred embodiment, the test control module 15 and theoperator interface 18 are provided as a single, integrated unit (namely,the intelligent display module 14) and share the same housing as well asat least some of the internal electronics. Other arrangements arepossible, however. For example, as can be easily imagined, it would alsobe possible to provide the test control module 15 and the operatorinterface 18 in the form of separate physical units, although thisarrangement is not preferred for reasons of increased cost and partscount. Both the test control module 15 and the operator interface 18 canbe obtained in the form of a single, integrated unit from AdvancedTechnology, Inc., Elkhart, Ind. 46517. This product provides a genericflat panel 4 line×20 character display 19, four button keypad 20,microprocessor 16, and memory that is capable of being programmed with aprogram (such as the diagnostic program 17) to customize the intelligentdisplay module for a particular application. Of course, a more (or less)elaborate intelligent display module could also be utilized.

[0025] Also in the preferred embodiment, the intelligent display module14 is semi-permanently mounted within the vehicle 10. Bysemi-permanently mounted, it is meant that the intelligent displaymodule 14 is mounted within the vehicle 10 in a manner that issufficiently rugged to withstand normal operation of the vehicle forextended periods of time (at least days or weeks) and still remainoperational. However, that is not to say that the intelligent displaymodule 14 is mounted such that it can never be removed (e.g., forservicing of the intelligent display module) without significantlydegrading the structural integrity of the mounting structure employed tomount the intelligent display module 14 to the remainder of the vehicle10. The intelligent display module 14 is preferably mounted in anoperator compartment of the vehicle 10, for example, in a storagecompartment within the operator compartment or on an operator panelprovided on the dashboard.

[0026] The operation of the test control module 15, and in particular ofthe microprocessor 16 to execute the diagnostic program 17, is shown anddescribed in greater detail below in conjunction with the flow chart ofFIG. 4. In general, the microprocessor 16 executes the diagnosticprogram 17 to diagnose subsystem faults, to display fault information,to maintain vehicle maintenance records, and to perform data logging forsystem diagnosis and/or for accident reconstruction. Depending on theapplication, it may be desirable to incorporate additional services aswell, or to incorporate fewer than all of these services.

[0027] The operator interface 18 includes the display 19 which is usedto communicate (and, in particular, to display) information to theoperator. For example, the display 19 is used to prompt the operator toenter information into the keypad 20, or to take certain actions withrespect to the vehicle during testing (e.g., bring the engine to aspecified RPM level). The display 19 is also used to display a menu orseries of menus to allow the operator to select a test to be performedor to select another service of the intelligent display module 14 to beutilized. The display 19 is also used to display status informationduring system startup and during testing, and to display any errormessages that arise during system startup or during testing. The display19 is also used to display input data and fault mode indicators fromcontrol systems 24-30, and any other information from additional vehiclesubsystems. The display 19 is also used to display information fromdiscrete sensors such as the sensors 22. The display 19 is also used todisplay the results of diagnostic tests that are performed (e.g., apass/fail message or other message).

[0028] Preferably, the display 19 displays all of this information tothe operator in a user-friendly format as opposed to in the form ofcodes that must be interpreted by reference to a separate test orservice manual. This is achieved in straightforward fashion by storingin the memory of the intelligent display module 14 information of thetype commonly published in such manuals to facilitate manualinterpretation of such codes, and using this information to perform thetranslation automatically. Likewise, as previously noted, the display 19is used to prompt the operator to take certain actions with respect tothe vehicle during testing and to otherwise step the operator throughany test procedures, without reference to a test manual. This allows theamount of operator training to be reduced.

[0029] The operator interface 18 also includes the keypad 20 which isused to accept or receive operator inputs. For example, the keypad 20 isused to allow the user to scroll through and otherwise navigate menusdisplayed by the display 19 (e.g., menus of possible tests to beperformed on the vehicle 20), and to select menu items from those menus.

[0030] As previously noted, it would also be possible to utilize a moreelaborate intelligent display module. For example, a more elaboratekeypad 20 could be utilized if more data entry capability is desired. Inthis regard, however, it is noted that the intelligent display module 14also preferably includes a communication port that allows the displaymodule to communicate with a personal computer 33 by way of acommunication link 36 (see FIG. 2). The personal computer 33 can be usedto retrieve, manipulate and examine data stored within the intelligentdisplay module 14. For example, if the intelligent display module 14includes a data logger as described below, the personal computer can beused to retrieve and examine the information stored by the data logger.Likewise, if the intelligent display module 14 implements a vehiclemaintenance jacket, the personal computer 33 can be used to retrieve andmodify data stored in the vehicle maintenance jacket. Further, using thepersonal computer 33, it is possible to integrate the diagnostic system12 with an interactive electronic technical manual (IETM), to allow theinteractive electronic technical manual to access the data availablefrom the diagnostic system 12.

[0031] The test interface module 21 accepts requests from theintelligent display module 14 for information from the sensors 22,retrieves the requested information from the respective sensor 22,converts input signals from the respective sensor 22 into a format thatis compatible with the network communication link 32, and transmits theinformation from the respective sensor 22 to the intelligent displaymodule 14 via the network communication link 32. The test interfacemodule 21 is therefore preferably implemented as a passive unit with nostandard broadcasts that burden the communication link 32. As a result,in operation, the test interface module 21 does not regularly transmitdata on the network communication link 32. Rather, the test interfacemodule 21 passively monitors the network communication link 32 forinformation requests directed to the interface module 21. When aninformation request is received, the test interface module 21 obtainsthe requested information from the relevant sensor 22, and thentransmits the requested information on the network communication link 32to the intelligent display module 14.

[0032] The test interface module 21 may, for example, include as manyinputs as there are sensors 22. Each input may include associatedswitches for configuring the input, an analog-to-digital converter toconvert analog signals to a digital format, and any other signalprocessing circuitry. The number of inputs is not important, since it ispossible to use fewer test interface modules each with a larger numberof inputs, or more test interface modules each with a smaller number ofinputs. The number of inputs is not limited in any particular way and isdetermined by need.

[0033] In practice, the test interface module 21 may be a commerciallyavailable unit capable of putting information from discrete sensors ontoa network communication link such as SAE (Society of AutomotiveEngineers) J1708. The test interface module 21 preferably also meetsapplicable standards for underhood installation, such as SAE J1455, toallow the test interface module to be located in close proximity to thesensors 22 to reduce wiring. The test interface module may, for example,be obtained from Advanced Technology Inc., Elkhart, Ind. 46517 (PN3246282). Again, however, a wide range of devices of varyingconstruction and complexity could be utilized to implement the testinterface module 21.

[0034] The test interface module 21 is connected to the plurality ofsensors 22 which are each capable of obtaining information pertaining tothe health and operation of a vehicle subsystem. “Health” and“operation” are interrelated and information that pertains to one will,at least to some extent, pertain to the other as well. The sensors 22are discrete sensors in the sense that they are not integrally providedwith the control systems 24-30 and associated controlled mechanicalsystems (e.g., engine, transmission, and so on) 34-40. The sensors areadd-on devices that are used only in connection with the intelligentdisplay module 14. In general, discrete sensors are preferably only usedwhen the information provided by the sensor is not otherwise availableon the network communication link 32. In FIG. 2, the sensors 22 areshown to include a fuel filter inlet pressure sensor 22 a, fuel pumpoutlet pressure sensor 22 b, fuel return pressure sensor 22 c, oilfilter sensors 22 d, an air cleaner pressure sensor 22 e, a fueldifferential pressure switch 22 f, and a shunt resistor 22 g (used todetermine compression imbalance based on unequal current peaks in thestarter current).

[0035] In addition to the intelligent display module 14 and the testinterface module 21, the diagnostic system 12 also includes a pluralityof additional vehicle control systems 24-30, as previously noted. Asshown in FIG. 2, the control system 24 is a central tire inflationcontrol system that controls a central tire inflation system (CTIS) 34,the control system 26 is an anti-lock brake control system that controlsan anti-lock brake system (ABS) 36, the control system 28 is atransmission control system that controls a transmission 38, and thecontrol system 30 is an engine control system that controls an engine40. The vehicle subsystems formed by the mechanical systems 34-40 andassociated control systems 24-30 are conventional and are chosen inaccordance with the intended use of the vehicle 10.

[0036] The control systems 24-30 each store information pertaining tothe health and operation of a respective controlled system. The controlsystems 24-30 are capable of being queried and, in response, making therequested information available on the network communication link 32.Because the vast amount of information required for performing mostdiagnostic tests of interest is available from the control systems 24-30by way of the network communication link 32, it is possible todrastically reduce the number of discrete sensors 22 that are required.Thus, as just noted, discrete sensors are preferably only used when theinformation provided by the sensor is not otherwise available on thenetwork communication link 32.

[0037] Typically, each of the control systems 24-30 comprises amicroprocessor-based electronic control unit (ECU) that is connected tothe network communication link 32. When the intelligent display module14 requires status information pertaining to one of the mechanicalsystems 34-40, the intelligent display module 14 issues a request forthe information to the respective one of the control systems 24-30. Therespective control system then responds by making the requestedinformation available on the network communication link 32.

[0038] Typical ECUs for transmission and engine control systems arecapable of producing fault codes and transmitting the fault codes on thenetwork communication link 32. Depending on the type of fault, the faultcodes may be transmitted automatically or alternative only in responseto a specific request for fault information. Typical ECUs for centraltire inflation systems and anti-lock brake systems also transmit faultcodes but, in most commercially available systems, fault codes aretransmitted only in response to specific requests for fault information.When a fault code is transmitted on the network communication link 32,the intelligent display module 14 receives the fault codes from thenetwork communication link 32, interprets the fault codes, and displaysthe interpreted fault codes to a human operator using the display 19.

[0039] Referring now to FIG. 3, in general, during operation, thedisplay 19 displays menus to the operator and the keypad receivesoperator inputs used to navigate the menu, make menu selections, andbegin testing. Assuming other services are also provided, the operatoris first prompted to select an option from among a list of options thatincludes options of other services provided by the intelligent displaymodule 14. The list of options may include, for example, an option 50 toperform vehicle diagnostic testing, an option 52 to view engine codes,an option 54 to view transmission codes, an option 56 to view ABS codes,an option 58 to view CTIS codes, an 60 option to view and/or modify datain the vehicle maintenance jacket, and an option 62 to view informationstored in a data logger. Given that the display 19 is a four linedisplay in the preferred embodiment, a vertically sliding winding 64 isused to scroll through the options, and the user presses a select buttonon the keypad 20 when a cursor 66 is positioned on the desired option.As previously noted, other options may also be provided.

[0040] Referring now to FIG. 4, a flow chart showing the operation ofthe diagnostic system of FIGS. 1-2 to perform a diagnostic test isillustrated. In connection with military vehicles, the diagnostic system12 may for example be made capable of performing the followingdiagnostic tests, all of which provide information pertaining to thehealth and operation of the tested subsystem:

[0041] [0041] Test Exemplary Description and Measurement TestApplication Range(s) ENGINE TESTS Engine RPM (AVE) Measures averagespeed of  50-5000 RPM engine crankshaft. Engine RPM, Measures crankingRPM.  50-1500 RPM Cranking SI only Performed with ignition ON. Inhibitspark plug firing allowing cranking without starting. Power TestMeasures engine's power 500-3500 RPM/s (RPM/SEC) producing potential inunits of RPM/SEC. Used when programmed engine constants andcorresponding Vehicle Identification Number (VID) have not beenestablished. Power Test (% Measures percentage of 0-100% Power) engine'spower producing potential compared to full power of a new engine.Compression Evaluates relative cylinder 0-90% Unbalance (%) compressionand displays percent difference between the highest and the lowestcompression values in an engine cycle. IGNITION TESTS Dwell Angle (TDC)Measures number of 10-72 @ degrees that the points are 2000 RPM closed.Points Voltage Measures voltage drop 0-2 VDC (VDC) across the points(points positive to battery return). Coil Primary Measures voltageavailable 0-32 VDC at the coil positive terminal of the operatingcondition of the coil. FUEL/AIR SYSTEM TESTS Fuel Supply Pressure 0-100psi (psi) Fuel Supply Pressure This test measures the 0-10 psi (psi)outlet pressure of the fuel 0-30 psi pump. 0-100 psi 0-300 psi FuelReturn Pressure Measures return pressure to 0-100 psi (psi) detectreturn line blockage, leaks, or insufficient restrictor back pressure.Fuel Filter Pressure Detects clogging via PASS/FAIL Drop (PASS/FAIL)opening of a differential pressure switch across the secondary fuelfilter. Fuel Solenoid Measures the voltage 0-32 VDC Voltage (VDC)present at the fuel shutoff solenoid positive terminal. Air CleanerPressure Measures suction vacuum in 0-60 in. H₂O Drop (RIGHT) (In airintake after the air H₂O) cleaner relative to ambient air pressure todetect extent of air cleaner clogging. Air Cleaner Pressure Second aircleaner on dual 0-60 in. H₂O Drop (LEFT) (In H₂O) intake systems.Turbocharger Outlet Measures discharge 0-50 in. Hg Pressure (RIGHT) (Inpressure of the Hg) turbocharger. Turbocharger Outlet Secondturbocharger on 0-50 in. Hg Pressure (LEFT) (In dual intake systems. Hg)Airbox Pressure Measures the airbox 0-20 in. Hg (In Hg) pressure of twostroke 0-50 in. Hg engines. This measurement is useful in detecting airinduction path obstructions or leaks. Intake Manifold Spark ignitionengine intake 0-30 in. Hg Vacuum (In Hg) system evaluation. IntakeManifold Spark ignition engine intake 0-30 in. Hg Vacuum Variationsystem evaluation. (In Hg) LUBRICATION/COOLING SYSTEM TESTS Engine OilPressure Measures engine oil 0-100 psi (psi) pressure. Engine Oil FilterMeasures the pressure drop 0-25 psi across the engine oil filter asindicator of filter element clogging. Engine Oil Primarily applicable toair 120-300° F. Temperature (° F.) cooled engines. Requires transduceroutput shorting switch on vehicle to perform system zero offset test.Engine Coolant Transducer output shorting 120-300° F. Temperature (° F.)switch on vehicle required. STARTING/CHARGING SYSTEM TESTS BatteryVoltage Measure battery voltage at 0-32 VDC (VDC) or near batteryterminals. Starter Motor Measures the voltage 0-32 VDC Voltage (VDC)present at the starter motor positive terminal. Starter NegativeMeasures voltage drop on 0-2 VDC Cable Voltage Drop starter path. A highvoltage (VDC) indicates excessive ground path resistance. StarterSolenoid Measures voltage present at 0-32 VDC Volts (VDC) the startersolenoid's positive terminal. Measures current through battery groundpath shunt. Starter Current, Measures starter current. 0-1000 A Average(amps) 0-2000 A Starter Current First Provides a good overall 0-1000 APeak (Peak Amps, assessment of complete 0-2000 A DC) starting system.Tests condition of the starting circuit and battery's ability to deliverstarting current. The measurement is made at the moment the starter isengaged and prior to armature movement. Peak currents less than nominalindicate relatively high resistance caused by poor connections, faultywiring, or low battery voltage. Battery Internal Evaluate batterycondition 0-999.9 mohm Resistance by measuring battery (Milliohms)voltage and current simultaneously. Starter Circuit Measures thecombined 0-999.9 mohm Resistance resistance of the starter (Milliohms)circuit internal to the batteries. Battery Resistance Measures rate ofchange of 0-999.9 mohm/s Change battery resistance as an (Milliohms/sec)indicator of battery condition. Battery Current Measures current to orfrom −999-1000 A the battery. −999-2000 A Battery Electrolyte Determineswhether PASS/FAIL Level (PASS/FAIL) electrolyte in the sensed cell is ofsufficient level (i.e., in contact with electrolyte probe).Alternator/Generator Measures output voltage of 0-32 VDC Output Voltagegenerator/alternator. (VDC) Alternator/ Measures voltage present at 0-32VDC Generator Field alternator/generator field Voltage (VDC) windings.Alternator/ Measures voltage drop in 0-2 VDC Generator Negative groundcable and Cable Voltage Drop connection between (VDC)alternator/generator ground terminal and battery negative terminal.Alternator Output Measures voltage output at 0-3 VAC Current Sense thecurrent transformer in (VAC-RMS) 650 ampere alternator. Alternator ACMeasures alternator output 0-22 VAC Voltage Sense voltage. (VAC-RMS)

[0042] In general, the specific diagnostic tests that are performed willbe selected depending on the application, including the type ofequipment utilized by the vehicle 10. Most or all tests may be simple innature from a data acquisition standpoint, involving primarily bringingthe vehicle to a particular operating condition (e.g., engine speed), ifnecessary, and obtaining information from a suitable transducerconstructed and placed to measure the parameter of interest, althoughmore elaborate tests could also be utilized. Any number of differentvehicle parameters can be measured, each providing a separate data pointregarding the operational health of the vehicle. By providing anoperator with enough data points regarding the operational health of thevehicle, the operator can use this information in a known way todetermine whether the vehicle is in good working order, or whether somesubsystem or component thereof needs to be repaired or replaced.

[0043] At step 102, once the vehicle diagnostic option is selected, thedisplay 19 displays a menu of various tests that are available to theoperator, and the operator is prompted to select a test from the testmenu. Again, the list of options may comprise dozens of options, such assome or all of those listed above, and/or tests other than those listedabove, and the operator can scroll through the menu and selected thedesired option.

[0044] At Step 104, the operator is prompted to perform a vehiclerelated action. This step, which may or may not be necessary dependingon the type of test performed, may be used to prompt the operator tostart the engine to develop fuel pressure, oil pressure, and so on,depending on which vehicle parameter is tested. For example, if it isdesired to test the operational health of the battery, then the operatormay be prompted to engage the starter for a predetermined amount of timeto establish a current draw on the battery.

[0045] At Step 106, the intelligent display module 14 issues a requestfor information from the test interface module 21and/or from one or moreof the control systems 24-30. As previously noted, the test interfacemodule 21 does not continually broadcast information on the networkcommunication link 32, because the sensors 22 connected to the testinterface module are used only for diagnostic testing and becausepresumably diagnostic testing will be performed only infrequently.Therefore, when the intelligent display module 14 needs information fromone of the sensors 22 pursuant to a test requested to be performed bythe operator at the operator interface 18, the intelligent displaymodule 14 requests the test interface module 21 for this information.

[0046] Alternatively, the needed information may be of a type that isavailable from one of the control systems 24-30. The control systems24-30 are not only able to acquire information from sensors locatedwithin the systems 34-40, but are also able to maintain informationderived from sensors located within the systems 34-40. For example, theengine control system 30 may maintain information pertaining to theaverage RPM of the engine, which is a parameter that is not directlymeasurable but that can be easily calculated based on parameters thatare directly measurable. Through the network communication link 32, allof this information is made available to the diagnostic system 12. Whenthe intelligent display module 14 needs information from one of thecontrol systems 24-30 pursuant to a test requested to be performed bythe operator at the operator interface 18, the intelligent displaymodule 14 requests the respective control system for this information.

[0047] At Step 108, the requested information is retrieved from one ofthe sensors 22 by the test interface module 21, or from memory or aninternal sensor by the respective control system 24-30. At step 110, theinformation is transmitted from the test interface module 21 or from oneof the control systems 24-30 to the intelligent display module 14 by wayof the network communication link 32.

[0048] At step 112, the input status information is processed at theintelligent display module 14. For example, if fuel supply pressure ismeasured by one of the sensors 22, then the measured fuel supplypressure may be compared with upper and lower benchmark values todetermine whether the fuel pressure is at an acceptable level, orwhether it is too high or too low. Finally, at step 114, the results ofthe test are displayed to the operator.

[0049] As has been previously noted, in addition to performingdiagnostic tests, the intelligent display module 14 can also be used toprovide other services to an operator. For example, the intelligentdisplay module 14 can be used to allow the operator to view enginecodes, to view transmission codes, to view ABS codes, and to view CTIScodes. In practice, these services can be implemented simply by allowingacquiring the respective codes from the respective control system 24-30,and displaying the codes to the operator. Additionally, the controlsystems 24-30 may automatically transmit fault information on thenetwork communication link 32, and the intelligent display module 14 canlisten for such fault information and display the fault information tothe user when it appears on the network communication link 32.

[0050] The intelligent display module 14 also includes sufficient memoryto allow maintenance information to be stored therein to implementmaintenance jacket functionality. The maintenance log may consist of atable comprising a variety of fields, such as registration numbers,chassis serial number, vehicle codes, and dates and descriptions ofmaintenance actions performed. This information may be retrieved andmanipulated utilizing the computer 34 when the vehicle 10 is taken to amaintenance depot. If the computer 34 is provided with an interactiveelectronic technical manual (IETM) for the vehicle 10, this allows theIETM to have access to all of the diagnostic data acquired by theintelligent display module 14 as well as all of the maintenance datastored by the intelligent display module 14. This greatly enhances theability to perform vehicle maintenance and diagnostics on the vehicle10.

[0051] Additionally, sufficient memory capacity is preferably providedso that status information from the test interface module 21 as well asthe control systems 24-30 can be sampled and stored at frequent, regularintervals in a circular data queue (i.e., with new data eventuallyreplacing old data in the circular queue). This allows the intelligentdisplay module 14 to provide a data logger service so that input dataacquired over a period of time can be viewed to allow an assessment ofdynamic conditions leading to a fault to be evaluated. Additionally, thevehicle is preferably provided with one more sensors that indicatewhether a severe malfunction (e.g., the vehicle being involved in anaccident) has occurred. When inputs from these sensors indicates that asevere malfunction has occurred, data logging is stopped, so that dataleading up to the severe malfunction is stored in a manner similar to aso-called “black box recorder.”

[0052] Referring now to FIG. 5, a schematic view of another type ofequipment service vehicle 110 that utilizes the diagnostic system 12 ofFIGS. 1-4 is shown. The equipment service vehicle 110 is a firefightingvehicle and comprises a water dispensing system 115 including waterhoses, pumps, control valves, and so on, used to direct water at thescene of a fire. The firefighting vehicle 110 may also comprise a foamdispensing system 118 as an alternative fire extinguishing system. Thefirefighting vehicle 110 also comprises emergency lighting 124, whichmay in practice be red and white or red, white and blue flashing lights,as well as an emergency horn 126 and an emergency siren 128 used, amongother things, for alerting motorists to the presence of the firefightingvehicle 110 in transit to or at the scene of a fire. The firefightingvehicle 110 may also comprise an extendable aerial 131 that supports abasket 132 used to vertically carry firefighting personnel to anemergency situation at the scene of a fire. The diagnostic system 12 maybe used to diagnose vehicle malfunctions in the manner described abovein connection with the vehicle 10, as well as to diagnose malfunctionsof the specialized systems described above found on firefightingvehicles.

[0053] Referring now to FIG. 6, a schematic view of another type ofequipment service vehicle 210 that utilizes the diagnostic system 12 ofFIGS. 1-4 is shown. The equipment service vehicle 210 is a mixingvehicle such as a cement mixing vehicle. The mixing vehicle 210comprises a rotatable mixing drum 215 that is driven by engine powerfrom the engine 40 via a power takeoff mechanism 220. Rotation of themixing drum 215 is controlled under operator control using a controlsystem 225. The mixing vehicle 210 also includes a dispenser 230 thatdispenses the mixed matter or material, for example, mixed cement. Thediagnostic system 12 may be used to diagnose vehicle malfunctions in themanner described above in connection with the vehicle 10, as well as todiagnose malfunctions of the specialized systems described above foundon mixing vehicles.

[0054] Referring now to FIG. 7, a schematic view of another type ofequipment service vehicle 310 that utilizes the diagnostic system 12 ofFIGS. 1-4 is shown. The equipment service vehicle 310 is a refusehandling vehicle and comprises one or more refuse compartments 315 forstoring collected refuse and other materials such as goods forrecycling. The refuse handling vehicle 310 also includes a hydrauliccompactor 317 for compacting collected refuse. The hydraulic compactor317 is driven by engine power from the engine 40 via a power takeoffmechanism 320. The refuse handling vehicle may also include an automaticloading or tipping system 325 for loading large refuse containers andfor transferring the contents of the refuse containers into one of thecompartments 315. The loading system 325 as well as the hydrauliccompactor may controlled under operator control using a control system330. The diagnostic system 12 may be used to diagnose vehiclemalfunctions in the manner described above in connection with thevehicle 10, as well as to diagnose malfunctions of the specializedsystems described above found on refuse handling vehicles.

[0055] Referring now to FIG. 8, a schematic view of another type ofequipment service vehicle 410 that utilizes the diagnostic system 12 ofFIGS. 1-4 is shown. The equipment service vehicle 410 is a snow removalvehicle and comprises a snow removal device 415 which may, for example,be a rotary blower, plow, or sweeper. The snow removal device 415 may bedriven by engine power from the engine 40 via a power takeoff mechanism420 to remove snow from a region near the snow removal vehicle 410 asthe snow removal vehicle 410 is moving. The diagnostic system 12 may beused to diagnose vehicle malfunctions in the manner described above inconnection with the vehicle 10, as well as to diagnose malfunctions ofthe specialized systems described above found on snow removal vehicles.

[0056] Advantageously, due to the utilization of a network architecturein the preferred embodiment, the diagnostic system is able to usesensors and other sources of information that are already provided onthe vehicle, because it is able to interact with other vehicle controlsystems such as the engine control system, the anti-lock brake controlsystem, the central tire inflation control system, and so on, via anetwork communication link. The fact that the diagnostic system isconnected to these other systems, which are all typically capable ofproviding a vast array of status information, puts this statusinformation at the disposal of the diagnostic system.

[0057] Further, due to the utilization of an intelligent display modulein the preferred embodiment, it is possible for the intelligent displaymodule to be connected to the network communication link and collectinformation as necessary for a variety of purposes. Thus, the preferredintelligent display module is microprocessor-based and is capable ofexecuting firmware to provide additional functionality such as datalogging, accident reconstruction, and a vehicle maintenance record.Again, this functionality can be achieved by taking advantage of theinformation available from the vehicle subsystems by way of the networkarchitecture.

[0058] Moreover, by mounting the intelligent display module on board thevehicle in the preferred embodiment, for example, in an operatorcompartment, it is not necessary to bring the vehicle to a maintenancedepot to have vehicle malfunctions diagnosed. The services offered bythe intelligent display module are available wherever and whenever thevehicle is in operation.

[0059] Many other changes and modifications may be made to the presentinvention without department from the spirit thereof. The scope of theseand other changes will become apparent from the appended claims.

What is claimed is:
 1. An equipment service vehicle comprising: (A) anetwork communication link; (B) a plurality of vehicle subsystems; (C) asensor, the sensor being configured to obtain health and operationinformation for a vehicle device; (D) an on-board diagnostic systemincluding an on-board test control module and an on-board operatorinterface, the on-board operator interface displaying a plurality oftest options to an operator and receiving a selection of a test from theoperator, the test control module being connected to at least some ofthe plurality of vehicle subsystems by way of the network communicationlink, the on-board test control module transmitting a request forinformation pertaining to the health and operation of the vehicle deviceon the network communication link; and (E) a test interface module, thetest interface module being connected to the sensor, the test interfacemodule being connected to the on-board test control module by way of thenetwork communication link, the test interface module receiving therequest for information pertaining to the health and operation of thevehicle device, the test interface module acquiring the requestedinformation from the sensor and transmitting the requested informationto the test control module; and wherein the test control module receiveshealth and operation information from one of the respective vehiclesubsystem or the test interface module or both and wherein the operatorinterface displays results of the test to the operator; wherein theselection is a first selection and the test is a first test, wherein theoperator interface receives a plurality of additional selections of aplurality of additional tests, and wherein the operator interfacedisplays results of the plurality of additional tests to the operator.2. A diagnostic testing method to be executed by an on-board diagnosticsystem of an equipment service vehicle having a plurality of subsystems,the method comprising: displaying a plurality of test options to anoperator using an on-board operator interface, the operator interfacebeing connected to a test control module; receiving an operator inputusing the operator interface, the input being indicative of a selectionmade by the operator, the selection indicating a test selected by theoperator; performing the selected test on the vehicle using a sensor orat least one of the plurality of vehicle subsystems or both, theplurality of subsystems being connected to the test control module byway of a network communication link, the sensor being configured toobtain health and operation information for a vehicle device, the sensorbeing connected to a test interface module that is connected to thenetwork communication link; acquiring health and operation informationpertaining to results of the test from the at least one vehiclesubsystem or from the test interface module using the sensor or fromboth; transmitting the health and operation information from the testinterface module or the at least one vehicle subsystem or both to thetest control module by way of the network communication link; displayingthe results of the test to the operator using the operator interface;and wherein the test is a first test, and wherein the foregoing stepsare repeated such that results of a plurality of additional tests aredisplayed.
 3. A military vehicle comprising: a plurality of subsystems,an on-board diagnostic system, the on-board diagnostic system includingan operator interface, a test control module, a test interface module,and a sensor, the operator interface being connected to the test controlmodule, the sensor being connected to the test interface module, thetest control module being connected to the test interface module and tothe plurality of subsystems by way of a network communication link, theoperator interface being at least semi-permanently mounted on-board thevehicle, the test control module being programmed to cooperate with theoperator interface, the sensor, the test interface module, and theplurality of subsystems to display a plurality of test options to anoperator using the operator interface; receive an operator input usingthe operator interface, the input being indicative of a selection madeby the operator, the selection indicating a test selected by theoperator; perform the selected test on the vehicle using the sensor orat least one of the plurality of vehicle subsystems or both, the sensorbeing configured to obtain health and operation information for avehicle device; acquire health and operation information pertaining toresults of the test from the at least one vehicle subsystem or from thetest interface module using the sensor or from both; transmit the healthand operation information from the test interface module or the at leastone vehicle subsystem or both to the test control module by way of thenetwork communication link; and display the results of the test to theoperator using the operator interface; and wherein the military vehicleis capable of travelling on unimproved terrain and through at leastthree feet of water.
 4. A military vehicle according to claim 3, whereinthe plurality of vehicle subsystems include an engine system includingan engine control system and a transmission system including atransmission control system, wherein the engine control system and thetransmission control system are each capable of producing fault codesand transmitting the fault codes on the network communication link, andwherein the test control module and the operator interface incombination are capable of receiving the fault codes from the networkcommunication link and displaying the fault codes to a human operator.5. A military vehicle according to claim 4, wherein the fault codes aredisplayed in an interpreted format.
 6. A military vehicle according toclaim 3, wherein the on-board diagnostic system stores a vehiclemaintenance record, the vehicle maintenance record comprising adescriptive log of maintenance activities performed on the vehicle.
 7. Amilitary vehicle according to claim 3, further comprising a memory thatstores a running log of health and operation information pertaining tothe vehicle.
 8. A military vehicle according to claim 3, wherein thetest interface module is a separate unit from the sensor.
 9. A militaryvehicle according to claim 3, wherein the operator interface and thetest control module are provided as a single integrated unit.